Hey Randy et al,
Sorry been out of touch since I'm setting up a "ugh!!" PC lab here in town. 28 computers and a cabling nightmare.
So here's what I think is the pertinent info:
screen starts switching between primary colors....then freezes.....Sometimes it lets me log on, then freezes.
also:
freezing at the Apple screen
red > green > blue > white and repeat.
So when you see that repeating primary colors you'd first think it's the LVDS connector. However the fact that it's also in the external display and the "freezing" part points you directly at the GPU. Since the iBook and Macs in general are GUI architecture any fault with the GPU will cause a freeze.
So based on experience with the early iBook G3s. Symptoms like this were sometimes caused by a failure of the BGA on the GPU. This was easy to test in the G3s since the GPU was easily available on the bottom of the logic board.
In the G4 it's under that large heat sink on top (toward the front) so a pressure diagnostic is very difficult. I've never been able to diagnose a BGA failure in a G4. If that were the case a reball would be in order.
The final and more problematic problem is a failure of the GPU itself. In a G3 I did manage a repair by finding an identical GPU on a Dell laptop board and having Superior swap it in. However in these later G4s the chip is a ATI Mobility Radeon 9550 4x AGP and if I remember the research I did on a 1.42 with this problem I couldn't find a cheap replacement donor from a PC laptop.
That coupled with the undependable nature of Superior and perhaps the other place in Arizona has left that 1.42 sitting in a box under my bench.
I'm still looking for a way to do that however. (Never give up!)
Richard